105 mm x 260 mm x 60 mm NACHI NP 421 cylindrical roller bearings

LET OUR 105 mm x 260 mm x 60 mm NACHI NP 421 cylindrical roller bearings 105 mm x 260 mm x 60 mm EXPERTS GET BEARING PRECISION AXLE CORP. YOU THE PARTS YOU NEED. 175 kN P60°

What is NP 421 bearing interchange？